Expecto Patronum Potterlock
by Jessica Hughes
Summary: The new defence against the dark arts teacher has something different in store for the second-years.
1. Gosh!

Sherlock flicked the feather lazily up higher into the air with his wand. He sat on the grass with his best friend John. John adjusted his gold and red tie nervously, taking note of Sherlock's loose blue and silver one. They were enjoying the sunshine during a free period, looking out over Hogwarts. A few other students chatted around them; Irene Adler, a sly but amazingly sexy Slytherin stared into a mirror as she reapplied red lipstick; Molly Hooper, an adorable, bubbly, Hufflepuff. Like John she didn't fit very well into friend groups, and usually tagged around with people who weren't the best role models. She sat next to Irene, reading from "Hogwarts; A History". And behind the trees where they _thought_ nobody could see them, were Michael Anderson and Sally Donovan, both Slytherin. Although one cannot be certain of the events happening behind the screen of branches, Sally was sure emitting strange noises. Sherlock licked his lips as the feather dropped to the floor.

"Rumours would seem that we have a new Defence Against The Dark Arts teacher." he remarked dryly. "Maybe this term we might get some work done- touch wood." he finished, tapping his wand with his index finger. John remained silent. For a while all was quiet, albeit the occasional moan or grunt from the trees behind them.

"Sherlock?" John piped after a few minutes, "Do you know anything about patronus'?"

Sherlock frowned. "I read something once, in the restricted section, I didn't pick much up though, why?"

John completely ignored Sherlock's questioning but continued. "Wait; how did _you _get into the restricted section?"

Sherlock grinned, sitting up and starting to pack up the books scattered around them.

"Speaking of which," he chirped, "we have Defence Against The Dark Arts now."


	2. Excuse me?

Their footsteps echoed on the stone walls around them as the walked up a flight of stairs that changed directions as they walked. Sherlock had lost track of the days (unusual for him) and lead John up a staircase which changes on a Tuesday. They were now late for class, and John was sweating profusely as he was determined to make a good impression on his new teacher, "_A bit late now_." he moaned under his breath.

They reached the fourth floor and Sherlock smiled at John nervously before pushing the door open tenderly. All of his classmates were gathered around the front table, looking obediently into the soft face of the professor. He had greying hair and what Sherlock could hear by the conversation as he entered the room, a thick London accent. "Muggle born maybe?" Sherlock thought. On the whiteboard, written in neat, swirly handwriting he had written his name. "Prof. Lestrade" it said.

(To say the least, he looked pretty cool; he seemed calm in front of his new students and he wore pretty muggle-ish clothing, except for the long robes he wore over a green jumper. Nobody turned as they entered the room quietly, the students too engaged in what Lestrade was saying to be bothered by the slight creak of a door. They sidled into the classroom slowly before joining the back of the crowd to join in on the class discussion.

The Gryffindors and Ravenclaws always took D.A.T.D.A with the Hufflepuffs which Sherlock liked. The Hufflepuffs weren't very smart but they didn't slow down the learning of others with tedious questions which had been answered a few moments prior. Sherlock despised lessons with the Slytherins. There's one brand of "full of yourself" which is _perfectly_ acceptable,but there's another (common among Slytherins) that makes Sherlock's stomach turn. Potions with Professor Moriarty is the lesson Sherlock despises. He tries his best to enjoy and engage but Moriarty is particularly biased toward the Slytherins, awarding them with unnecessary house points, and deducting them from the Ravenclaws. To add to the misery in potions, John isn't there to share the lesson so Sherlock has to partner with Dimmock, who he doesn't get on with very well. Anderson's always on his case, spiking Sherlocks potions, stealing his ingredients, rigging his scales, scribbling in his text books, the full monty. Sherlock was just thinking of a way to turn Anderson's skin purple when he heard a faint voice in the distance.

"Excuse me? Hello?"

Sherlock snapped out of his daydream to find the whole class staring at him, Lestrade holding up a string of something and his hands covered in strange-looking goo. Sherlock blushed.


	3. The patronus charm

Sherlock blushed.

"Having a bit of a day dream are we?" Lestrade said softly, raising his wand and making the goo disappear from his hands. When Sherlock didn't reply he smiled softly and turned back to the board. He grabbed the chalk and wrote down the word "Patronus."

"Now class," He began, sliding his hands into his pockets. "Headmaster Conan-Doyle wants me to teach you some useful things, now that it's rumoured you know 'o is back." A wave of silence glided over the crowd of students.

"It's rumoured that, You know-" he paused, scowled and shook his head. "No. It's rumoured that Moran -_oh don't act like you've never heard his name before_- has gained use of dementors. Who can tell me what a dementor is?"

John Watson raised his hand timidly from the back of the class. Lestrade raised himself up slightly to get a better view of the tiny boy.

"Yes, what's your name?"

"John Watson, professor."

"And can you tell me what a dementor is?"

"Yes professor. They're creatures that protect Barts, the wizard prison. Some say Barts is the most secure prison there is, and the dementors are the guards." He then closed his eyes for a second, remembering. "I read something once..." he whispered. "Oh, yes. Dementors feed off human happiness, and thus cause depression and despair to anyone near them. They can also consume a person's soul, leaving their victims in a permanent vegetative state and thus are often referred to as "soul-sucking fiends" and are known to leave a person as an "empty-shell."" he breathed out slowly, looking at Lestrades smiling face.

"Correct!" he beamed, "10 points to Gryffindor!"

The other students looked at John in surprised, this was advanced, _very advanced. _John looked proud of himself, oblivious to Sherlock's resentful gaze. He despised people being more intelligent than him.

"Now class," Lestrade turned to the blackboard once more, using his wand to tap the word. "Can anyone hazard a guess as to what a Patronus is?"

Sherlock didn't bother raising his hand. He spoke quietly in baritone.

"The Patronus Charm (_Expecto Patronum_) is an immensely complicated, very difficult spell that evokes a partially-tangible positive energy force known as a Patronus or spirit guardian. The charm was primarily designed for defence against Dementors against which there is no other protection."

Being pureblood, Sherlock grew up around magic. He'd read a book all about the patronus charm at the tender age of 7. The whole class seemed shocked, including Lestrade. Lestrade just gaped, rubbing his forehead in amazement.

"I-" he started. "Wow."


	4. Chapter 4

Lestrade smirked at Sherlock, in awe of his intelligence.

"Right then;" he continued, the cockney accent was thick. "So the patronus charm is emensly complicated. For the average student, you might have mastered it by the time we finish this unit. The trick is to focus very clearly on a happy memory, then the charm will erupt some sort of animal which will chase away the dementors. Any questions? No? Right then, "Expecto Patronum" is the incantation, focus on your happy memories and get going!"

Sherlock and John wondered to the back of the room, both trying to think of what made them happiest. Sherlock's eyes were glazed over in thought. John was finding it difficult to choose. Indeed, it should be something like when his parents had Harry, but somehow a different memory was popping up.

In this memory, it was a warm evening. Classes had finished for the summer, and they'd be travelling home the next day. Sherlock and John were alone down in the grounds, and there was something odd in the atmosphere. Sherlock was looking strange, he was smiling and laughing, and touching John's hands and legs. They found themselves getting to more and more sensitive topics, gradually moving closer to eachother, when at last John had his first kiss. Although he'd never admit it, that was the happiest he'd been in his life.

He looked around the room, seeing faces of strain. Some were still thinking of a strong memory and others were trying out the incantation. Sherlock walked up to John then.

"What's your memory? I'm having trouble."

John raised his eyebrows.

"You? Having trouble?"

Sherlock smirked, casually gliding a cold thumb across John's tanned hand, which was hanging by his side.

"Well, I think I have something in mind..."

He winked and walked off. John giggled before setting to work on the charm.  
He focused on the electricity and fireworks that happened with the kiss. The beautiful warm glow that was around them both when they cuddled afterwards.

Suddenly, without warning he yelled, "EXPECTO PATRONUM" and something amazing happened. His wand tip ignited, and out sprung a tiny little hedgehog which then leapt around the room. Lestrade started clapping as the other students scowled. Sherlock merely raised an eyebrow.

"That's amazing.." Lestrade stammered. "That sure must've been one powerful memory!" He concluded, clapping John firmly on the back.

"Yeah," he replied "I suppose it is." He whispered with a small smile.


	5. Chapter 5

_This is a more detailed version of John's memory which produced such a strong patronus._

_Potterlock;_

Exams had finished for the term. All of the students were enjoying the sunshine that bathed the grounds in a golden glow. At the furthest part of the grounds, beneath an old oak, John Watson, a second-year Gryffindor, and Sherlock Holmes, a second year Ravenclaw were engaged in conversation.

Sherlock's tie was gone, John's was loose. Both were de-robed and laying in the shade. Sherlock was smiling for a changed, finally relieved of the stress that came with the exams. John was giggling.

It was a beautiful day, it had been a long time since the pair had had any time alone.

"So, are you still going out with Mary?" Sherlock uttered. It was barely audible, but John heard it all the same. Afterall, they were lying extremely close to eachother right now.

John breathed out heavily and scratched his head.

"Well, I suppose but.."

"But?" Sherlock interrupted.

"I'm not sure how to describe it," he breathed after a few moments.

"Um. It's sort of like it never feels right? Like you are supposed to know when it's right, if that makes any sense. I don't know."

He closed his eyes and put his hands behind his head.

"Well does this happen with every girl you date?" Sherlock said softly.

"I suppose. I don't even know why I date so many of them, it just ends in her complaining that I'm 'fridgid' and then me dumping her."

"Hmm." Sherlock mumbled.

"What?"

John opened his eyes to see Sherlock sitting cross legged, scratching behind his ear. John raised his eyebrows, sat up and crossed his legs so that he was sitting directly infront of the taller boy.

"John?"

"Yes?"

That's when it happened. Sherlock slowly reached a hand down and placed it on the back of John's head. Initially he was startled at the out of place display of affection, but after a few minutes relaxed into the touch. Then he steadily lowered his face and pressed his soft, warm lips onto John's.

The sensation was amazing. Immediately fireworks erupted in his chest. His instinct told him to do something with his hands, so he brought them up to play with Sherlock's curls. The kiss intensified as did the electricity going through John's body.

Finally they drew away for breath. John was giggling, Sherlock was smirking.

"So, did that feel right?"

"Perfect."

They both lay down in the shade once more, intwining their fingers and closing their eyes.


	6. Chapter 7

Over the course of the next seven lessons everyone in the class had successfully produced a patronus. Sherlock managed it in the second lesson, producing a strong otter which sat on John's lap for a good five minutes before disappearing in a whisp of silver vapour. At the end of the unit even Molly Hooper had managed to produce a silky tabby cat which prowled between the desks.

Lestrade continued to be amazed at the rate that the class was working. It was their eigth of ten lessons, and he's managed to successfully convince Headmaster Conon-Doyle to weasle a dementor out of Barts for them to practice on.

Sherlock and John were stood at the back of the class, holding hands, oblivious to their class mates.

"Now." Lestrade began. "We've been practicing these patronus' in a classroom, where our brains are free to imagine the memories as clear as the night sky. But when I bring this dementor in, I hope you understand that it will be_ very different_." He paused, scanning the classroom.

"The room will go very cold, you will most likely start to shiver. You will feel as if ice is being stabbed into your heart. You will see and hear things of a disturbing nature. You will see things of your worst imagination. You may faint, be taken ill._ But you've got to focus on that happy memory._ There is no reason why any of you in this class can't tackle this dementor. Any questions?"  
After being reassured that if they fail to tackle the dementor Lestrade will do his on patronus, they filed out of the classroom so that they could do the task individually. Sherlock looked down at John as they stood at the front of the line.

"Are you okay? You look very pale." He remarked, frowning.

"I'm fine." John said with a weak smile._ Focus._ He thought. _Focus on the fireworks, the golden glow. Focus on the cheekbones, the curls, the perfect eyes. Focus on Sherlock. Focus on Sherlock._

And with that John was lead into the classroom first, Lestrade's hand firm on his shoulder.

"Have faith in yourself kiddo," Lestrade grinned.

John smiled back half heartedly. Focus on Sherlock. He repeated.

"Now, I'm going to summon the dementor, don't forget that happy memory. I will be here to help you get out of any danger. Are you okay?"

John nodded, raising his wand.

And then the room went cold. Horribly cold. He felt the goose bumps erupt all over his skin and he held back a violent shiver. The hairs on the back of his neck stood up as he saw the dementor glide into the room. It's sharp, rattling breath. It's cloak billowing behind. It's charred, scabbed hands reaching forward. He felt the cold stab into his heart. _No. Focus on Sherlock._ But it was so cold, so so cold. _The fireworks_. But he was slipping in and out of consiousness._ The electricity._ And suddenly he could hear screams, blood-curdling screams. They sounded so far away yet so close. And then he saw it, _Sherlock, dead on the floor_. _No_._ Expecto Patronum! The fireworks._ But he felt the tears fall, the room shift.

"Expec-" he began before staggering backwards into the wall.

"Expecto patronum!" Lestrade bellowed, a hawk erupting from his wand tip. The dementor disappeared immediately, the room temperature shot up and John managed to cling on to consiousness. He felt Lestrade crouch infront of him.

"You'll be okay." He said, breaking off three squares of dark chocolate. "Don't worry about it, I didn't expect anyone to get it first time."

He barely noticed that he was on his feet, being lead out of the door. Only once he had joined the back of the line of his classmates did he realise that he'll never be able to unsee that. Sherlock. Dead on the floor.

And the tears fell thick and fast.


	7. Chapter 8

After a mildly irritating lesson of potions Sherlock sped to the grounds. His own session with the dementor had gone fine, tackling it before it could even come close. But there were also a few whispers that John Watson had fainted, and he felt the flames of worry flicker feriosiously in his chest. After a few minutes he noticed him, hiding in the shadows of a tree in the far corner of the grounds, arms wrapped tightly around his knees.  
As he reached him he became increasingly more worried as John failed to lift his head.

"Alright? Are you alright?" Sherlock uttered, falling to his knees infront of John and checking him around in a state of urgence, a deep frown on his face. After a moment or two John finally lifted his face, and Sherlock actually wished that he hadn't. His cheeks were tear-stained, his eyes were red, puffy and blood-shot, and his skin was deathly pale. He looked dreadful, and Sherlock's heart stopped.

He wrapped his arms around the smaller boy, deciding for once that questioning him would be the "not good" thing to do. He patted him on the back as John burried his face into the shoulder of his boyfriend, still crying heavily. Sherlock kissed John's sandy head before pushing him away to get a good look at him. He'd never seen this boy like this. He'd seen him sad, of course he had. Family members dying, break ups... but nothing like this. It was like all life had been drained from him and he was just an empty shell filled with tears to cry out.

"It's okay John... I'm here now... It's okay..." He cooed soothingly, keeping John in a tight embrace.

"I love y-"  
"Oh look who it is! I've found Freak!" Sally Donovan screamed, signalling for her other Slytherin cronies to join her. Sherlock stood up, leaving John shaking on the ground.  
"Aw, well if it isn't Freak being a gay-lord in his natural habitat." She continued, stepping closer. She grinned maliciously.  
"Maybe a little curse will keep you and your snivelling friend from being so irritating." She lifted her wand. "IMPERI-"  
"LEVICORPUS!" and before Sally could finish her spell, she was hanging from the over-hanging tree by one leg.  
"Help! Anthea help me!" She screamed, flailing about. "You little-"

"That will teach you to mess with me and my boyfriend." Sherlock breated, glaring angrily at Donovan while helping a snivelling John up from the ground.

They made their way back up to the castle.

"Now, where were we? Ah, yes. I love you too." Sherlock smiled, stroking John's hair.


End file.
